The invention relates to paint spraying apparatus and particularly to automatically controlled paint spraying apparatus.
Such automatically controlled paint spraying apparatus is particularly applicable to the spraying of a succession of articles, such as for example, vehicle bodies, which are conveyed through a spray enclosure or booth past a spray station provided with one or more spray guns. The spray guns may be reciprocated perpendicular to the direction of travel of the articles so as to apply paint in strokes across the articles. Due to the varying shapes of articles to be sprayed, it is necessary to control the application of paint through the spray guns to provide varying length painting strokes in dependence on the part of the article adjacent the spray station. In many cases the spraying is carried out in booths having a carefully controlled atmosphere but due to the paint solvents, the atmospheres in spray booths are normally considered as hazardous requiring strict control on the equipment which may be used within the spray booth. Regulations controlling the equipment, particularly electrical equipment, which may be used in such hazardous areas has become more stringent and in order to avoid the need for flameproof or explosion-proof casings, more control equipment has been located in safe areas outside the spray booth and this has to be connected to limited control equipment within the spray booth. Due to the extent which it has been necessary to locate substantial parts of the control equipment outside the spray booth, extensive connections have been necessary between the equipment outside the booth and that inside the booth.